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Mori Hamada & Matsumoto

Work +81 3 6212 8330
Fax +81 3 6212 8230
Bangkok, Beijing, Fukuoka, Ho Chi Minh City, Osaka, Shanghai and 3 more

Atsushi Oishi

Work +81 3 5223 7767
Mori Hamada & Matsumoto

Work Department



Tax, Mergers and Acquisitions, General Corporate.


Admitted: Japan, 1998; New York., 2004. With Weil, Gotshal & Manges, New York (2003-2004); Partner of Hamada & Matsumoto (2006); Member of Task Force on Management Buy Out and Other Transactions, organized by Ministry of Economy, Trade and Industry (2007); Member of the Expert Committee on Anti-Tax Haven Legislation and Intangible Assets, organized by Ministry of Economy, Trade and Industry (2013)


Japanese & English


Dai-ni Tokyo Bar Association and The Japan Federation of Bar Associations, 1998


The University of Tokyo (LL.B.) New York University School of Law (LL.M., 2003).

Japan: Corporate and M&A

Corporate and M&A – Independent local firms

Within: Corporate and M&A – Independent local firms

The corporate practice at Mori Hamada & Matsumoto covers the full gamut of mandates and represents a client roster that includes blue-chip industrials, banks, financial institutions and private equity funds. Gaku Ishiwata and Shuhei Uchida recently acted for Asatsu DK in its acquisition by Bain Capital, and Naoya Shiota was part of the group which advised KKR on its acquisition of Calsonic Kansei and the subsequent squeeze-out procedure. Satoko Kuwabara  – who co-heads the practice with Ishiwata – and Takane Hori teamed up with Uchida to advise cryptocurrency exchange operator Coincheck on its sale to Manex, as well as the negotiation of possible transactions schemes, such as an earn-out mechanism (this follows Manex’s role as sponsor in a business improvement order imposed on Coincheck by the FSA). Other key senior names include Hajime Tanahashi, Tomohiro Tsuchiya and Atsushi Oishi. Among the team's impressive client list names such as SoftBank, Hitachi and Nomura also feature.

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Japan: Tax

Tax – Independent local firms

Within: Leading individuals

Atsushi Oishi Bengoshi - Mori Hamada & Matsumoto

Within: Tax – Independent local firms

Mori Hamada & Matsumoto's tax practice focuses on tax planning for corporate and individual clients and also has particular expertise in tax disputes and the tax elements of M&A, corporate reorganisations and cross-border transactions. The team fields a combination of lawyers, tax accountants and certified public accountants and has recently recruited two experienced practitioners in Yuko Maruyama from Yamada & Partners and Hirotaka Murakami from Deloitte Touche Tohmatsu Jaiyos Advisory Co., Ltd. Tax and M&A specialist Atsushi Oishi jointly leads the group with Makoto Sakai; Sakai is advising Sumitomo Mitsui Trust Bank on complex tax issues arising out of the 2017 amendment of the Corporation Tax Act. Associate Hiroshi Oyama is also recommended.

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Legal Developments by:
Mori Hamada & Matsumoto

Legal Developments in Japan

Legal Developments and updates from the leading lawyers in each jurisdiction. To contribute, send an email request to
  • Taking control of a Japanese publicly listed company:

    Introductory notes for successfully completing an M&A
  • Yuasa and Hara Business Law News

    Contents of the Issue Law on liability for breach of contract Review on the amendment to the cabinet office order on Corporate Disclosure

    The Minister for Justice, Alan Shatter (“the Minister”), has published the Criminal Justice Bill 2011 (“the Bill”). The main purpose of the Bill is stated to be “…to amend the criminal law to improve certain procedural matters and strengthen Garda investigative powers. The intention is that such improvements will assist in reducing the delays associated with the investigation and prosecution of complex crime, in particular white collar crime.”
  • Japan: New legislative framework for Sukuk

    The new framework passed in May 2011 will provide a solid legal platform for issuing Sukuk Ijarah under Japanese law. NAOKI ISHIKAWA highlights key legal structures and tax treatment in respect of the anticipated Sukuk issuances in Japan.
  • Yakult Bottle Acquired Distinctiveness

    Do you know about Yakult's delicious lactic acid drink which is contained in a small bottle? Yakult's lactic acid drink (hereafter referred to as "Yakult drink") is the most famous lactic acid drink in Japan and today is also being sold in many countries around the world. When you are enjoying Yakult drink, please keep in mind the case mentioned below.
  • Tax: Japan: International Joint Ventures

    Tax on international joint ventures. Country Q&A (Japan).
  • Japan: Recent Developments in Practice and Law

    The successful closing of two Islamic fi nance transactions which was announced in July 2010 by Nomura Holdings have paved a concrete path for Japanese corporations to consider overseas Islamic fi nance markets for their fund raising activities. The fi rst transaction was in Asia for the issuance of Sukuk Ijarah and the second was in the Middle East for the establishment of a Commodity Murabahah facility (Nomura Deals).
  • Renewable energy takes off in Japan

    Like many other countries, Japan has decided to reform its renewable energy (RE) policy, to dramatically increase the use of renewable energy. The core policy mechanism is a feed-in tariff (FIT). This chapter summarises the contemplated Japanese FIT and its practical impact on existing and future investment in this sector, providing an overview of:
  • Licensing - 2010

    Q & A on Licensing in Japan 
  • Law on the Civil Jurisdiction of Japanese Courts over Foreign Countries, etc.

    The Law has been enacted to clarify the scope of application of the civil jurisdiction of Japanese courts over foreign countries, etc., and set exceptions to civil preocedings involving foreign countries, etc., based on the United Nations Convention on the Jurisdictional Immunities of States and their property (UN Convention on Immunities) (see Article 1).